The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Internal combustion engines combust an air and fuel mixture within cylinders to drive pistons, which produces drive torque. In some types of engines, air flow into the engine may be regulated via a throttle. The throttle may adjust a throttle opening area, which increases or decreases air flow into the engine. As the throttle opening area increases, the air flow into the engine increases. A fuel control system adjusts the amount that fuel is injected to provide a desired air/fuel mixture to the cylinders and/or to achieve a desired torque output. Increasing the amount of air and fuel provided to the cylinders increases the torque output of the engine.
Operation of the engine may be controlled according to various parameters and characteristics. For example, the engine may be controlled to maximize volumetric efficiency, which indicates a ratio of the amount of air inducted into the cylinder by a piston to the total amount of air that can be inducted under static conditions. Various characteristics may be measured, estimated, and/or modelled to determine the volumetric efficiency of the engine.